摘要 |
An object of the present invention is to provide a method by which bonding at a low temperature is possible and an amount of metal contaminants in an SOI film is decreased. An embodiment of the present invention is realized in the following manner. A single crystal silicon substrate 10 surface-activated by a plasma-treatment and a quartz substrate 20 are bonded together at a low temperature, to which an external impact is given to mechanically delaminate silicon film from a single crystal silicon bulk thereby obtaining a semiconductor substrate (SOI substrate) having a silicon film (SOI film) 12. Next, the SOI substrate is subjected to a heat-treatment at a temperature of 600° C. to 1250° C. so that metal impurities accidentally mixed into an interface of the SOI film and the quartz substrate and into the SOI film in such a step as a plasma-treatment are gettered to a surface region of the silicon film 12. Then, in the end, a surface layer (gettering layer) of the silicon film 12 of the SOI substrate after the heat-treatment is removed to finally prepare an SOI film 13 and a semiconductor substrate (SOI substrate) is obtained.
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